Telephone system



Nov. 29, 19270 R. s. WILBUR TELEIHONE SYSTEM Filed Sept. 3, 1926 4 Sheets-Sheet 1 //2venf0r: Ray 5 Wllbur by 4 1477] 1 N. is v n Fl U i QW h N Nov. 29, 1927. 1,650,731

" R; S. WILBUR TELEPHONE SYSTEM Filed Sept. 5. 1926 4 Sheets-Sheet 2 mwnfar: Rayi Wllbur by 71/ flfw W R. S. wlLBUR TELEPHONE SYSTEM Filed Sept. 3. 1926 4 Sheets-Sheet 3 \R Um Nov. 29, 19.27. 1,650,731

R. s. WILBUR TELEPHONE SYSTEM Filed Sept. 3, 1926 4 Sheets-Sheet 4 Patented Nov. 29, 1927.

entree s'rarss ATENT" cri ics.

RAY S. WILBUR, OF LYNDHURST, NEW JERSEY, ASSIGNOR' TO BELL TELEPHONE LABO- RATORIES, INCORPORATED, 013 NEW YORK, N. Y., A CORFORATION OF NEW YORK.

mnnrnonn SYSTEM.

Application filed September 3, 1926. Serial no. 133,386.

This invention relates to telephone systems and particularly to improvements in methods and means for completing toll con nections. V

This invention is an improvement over present systems and contemplates the use of means whereby a single trunk between the call originatinpj o'll'ice and the toll oilice is employed for recording as well as completing the toll connection and whereby said recordingand completing of the connection 'is accomplished by a single toll operator. According to another aspect of the invention this arrangement may be applied to a twoi way toll line.

Another aspect of the invention is an ar-.

rangement.whereby a trunk used for recording and completing in one direction may be i used as an ordinary toll switching trunk for calls in the opposite direction. A considerable saving in cost in handling toll traffic is therefore effected.

The method and means'of handling toll position. Before a connection is completed through this trunk to the toll olhce and as a result of it being seized by the A operator, a signal is actuated at the toll switching operator's position indicating to this operator to connect her telephone set to the trunk. When this accomplished, a connection is completed through the trunk to the toll operator from the calling subscriber with the toll switching operators telephone set included in the connection so that when the calling subscriber now passes his own number and the desired subscrihers number to the toll operator, the toll switching operator listens in and the toll operator prepares the usual t record of the call. lVhen ts .ing operator hears the calling salt:

terminating in a toll switching operatorssw tching scribers number, she inserts the plug of the .trunk intoa multiple jack of thiscalling subscr bers line and restores the talkin key, at which time the connection to the op nected the trunk to the calling subscriber and the A operator is removed from the connection the toll operator receives a signalto this effect and now proceeds to complete the toll connection to the calling subscriber. When the calling subscriber hangs up and thettoll operator receives the usual signal to thisetlect she takes down the connection, whereupon the toll switching operator receives a disconnect signal and also removes the plug of the trunk from the calling sub scribersjack.

As outlined above therefore there is provided a means of recording and completing toll calls over a single trunk, and means for checking the calling subscribers number without releasing the calling subscribers line. An advantage of this method is that the A operators work relating to the extension of a toll connect-ion remains the same as in present practice, that is, her functions in this respect are practically the same as when she extends a connection between two local lines.

iVhen applied to a two way trunk the method othandling toll connections may take'the following form. For example, the

interconnecting trunk or toll line, as it may be called in this case, is provided with exactly identical equipment at both ends. In general, this equipment for the toll line may include a jack at the A operators positions and a plug at the toll switching operators positions at both ends. If an A operator connects with the incl: at one end of a toll line of this type toextend a connection over this line, the toll switching or outward operator at the same end is first notified by a distinctive signal that an outward connection a is desired. She will then connect her tele phone set tothe toll line and thus cause a distinctive signal to be given. to the toll inward operator the other at the he to connect teateie liene to the line. The inward operator then re quests from the calling subscriber the number of the wanted subscriber. The outward operator is listening "for this information and as it is passed she records it on'the usual ticket. The outward operator then asks the calling subscriber for his own number, records it on the me ticket and connects the toll line through a multiple jack to the calling subscribers line, while the inward operator completes the connectiontothe desired subscriber. The A operators cord will be disconnected from the toll line as in the previous case. "Vihile this call is being eie tended, the jacks associated with this toll line are made busy.

The invention has been illustrated in the accompanying drawings in which Figs. 1 and 2 show I an embodiment of the invention as 'ed to a combined recording andcom "trunlr line; Fig. l'sho'ws the outgoing end oi this line erminating in a jack at the A operators position and in aplug' at the toll switching operators position. A sub- .ICIllQBl S'l'lDB and an A operators cord are also shown in this figure in diagrammatict'orm; while '2 shows the incoming end oft-his trunk line terminating in a jack at the toll board. A toll operators cord circuit and a toll line are also shown in this figure in diagrammatic form.

Figs. 3 and l illustrate an embodiment of the invention as applied to a two-way toll line; Fig. 8 illustrating the equipment at one end of the line which terminates in ajack at the A. 'operators position and in a plug t the toll switching operatofis position. A subscribers line and an A operators cord are also shown this figure; while Fig. l illustrates the equipment at the opposite end of this toil line which is exactly identical to the equipment shown in Fig. 3.

Referring now so the illustration of the invention in Figs. 1 and 2 as applied to a combined recording and completing trunk line, the extension of toll connection over this trunk may be outlined as follows: A subscriber at line 1 calls an A operator in the usual manner and this operator in answering the call inserts plug 2 of cord A into jack 3 of line 1 and connects her telephone set '5 to the cord. toll connection by saying; Long distance. The A operatorwill then insert plug 6 of cord A into jack 7 ot the combined recording and completing trunk C. It should be understood o'l course that a plurality of such trunks are available to the A operator and that she tests for an idle trunk.

. This connection between cord A and trunk C causes the signal 10 at the toll switching operators position B to flash to indicate to the operator that a toll connection is desired. This connection also causes the plug ending portion of trunk C to be connected to the The subscriber of line 1 asks for a I jack ending portion while the portion 11 of trunk C leading to the toll board is temporarily cut off from the connection. The toll switching operator now actuates her'talking key 112 to coi'inncct her telephone set 14: to the trunk. is a result of this connection lamp 10 is ex tinguished' and the connection from jack 7 and plug 15 to the portion 11 of trunk {l is reestablished. Upon the completion of this connection. a circuit is established for the lighting of lamp 1'? at the toll board to indicate tov the toll operator at D that a long distance connection is desired. The toll operator will now insert plug 18 of cord D into jaclr 20 of trunl: C and connect her telephone set 21 to cord D thus establishing a communicating connection from her telephone set to the subscriber of line 1.

The toll operator at D will now notify the calling subscriber that she is ready to 6X tend a toll connection by answering; Long .dl t ance. The calling subscriber will then give the toll operator at D the number of the wanted subscriber as well as his own number. It will be remembered that the toll s vitch-ing operate at B is connected directly to the trunk C so that she may listen to the number passed from the subscriber to the toll operator. On the insertion of the plug 18 into jack 2O lamp 1? is extinguished and lamp 1-0 is lighted stcadilyindicating to the toll switching operator that the connection has been or; ended to the toll board.

litter the toll switching. operator at B has recorded the number passed by the calling subscriber to the toll operator, she will insert plug 15 into multiple jack 22 of the calling -subscribei"s line 1 and restore her talking key 12. The immediate result of this will be that the talking circuit through trunk C from the calling subscriber 1 will be com pleted over the toll switching operators branch of the trunk while the connection through the 1 1 operators cord A will be opened. The supervisory lamp 23 of cord circuit A will light to indicate to the A operator to take down the connection. hen the operator removes cord A from the connection aclr 7 remains busy and lamp 10 is extinguished while the usual. supervisory lamp in the toll cord D i extinguished to indicate to the toll opera-tor that the toll switching operator at P) has completed the connection to the calling subscriber. The toll operator may now complete connection to the wanted subscriber and conversation between the two subscribers will take place over trunk C through the branch leading to the toll switching operators position at B. Thus the complete operation of record ing, checking and completing a toll connection is accomplished over a single trunk.

' hen the calling subscriber hangs up, the supervisory lamp in the toll cord 1S lighted serving as a disconnect signal to the toll operator and when the toll'operator disconnects hercord the lamp 10 in the toll switching operators position is lighted indicating to the toll switching operator that conversation over this trunk has ended and that the connection maybe taken down.

This method of establishing, a connection not only provides means for recorrg, checking andcompleting a connection over a single trunk but the A operators functions in the connection remain practically the same as in the completing of a connection between two local subscribers lines.

It should be noted that this trunk line C may also be used as an ordinary toll switchingtrunk for calls in the opposite direction when the toll operator at l) connects to the toll switching operator at B. In this case the insertionof plug 18 into jack it) by the toll operator will light the lamp 10 at the toll switching operators position with a steady light which will indicate to this operator that a connection is desired from a toll operators position and the toll switch ing operator will then operate her talking key to connect the telephone set 14 to the trunk. This causes the extinguishing; of the usual supervisory lamp in the cord circuit D to notify the toll operator that the toll switchlug operator is connected with the trunk C.

The information for the desired connection is then passed by the toll operator to the toll. switching operator who completes the connection to the wanted subscribefs line and restores the listening lrey to normal;

The functions of these circuits of Figs. 1, and 2 in completing connections of the above type will now be described in detail. On the insertion of plug 6 into aclr 7 the following circuit is completed. Battery, lamp 23 sleeve terminals of plug (3 and jack 7, armature and back contact of relay 25, wind- .ing of relay 26 to ground. This causes the operation of relay 2(3,the winding of which is of such resistance that lamp 23 will light. The operation of relay 26 closes a connection for the flashing of lamp 10 as follows hattery, lamp 10, left-hand armature and back contact; of relay 27, left hand armature and front contact of relay 26, left-hand arina ture and back contact of relay 28 through the interrupter 29 to ground. The operation of relay 26 also closes circuits forv the open ation of relays 30 and 31 as follows: the circuit "for relay 30 extends from battery, winding of relay 30,0uter righthand armature and front contact of relay 26. upper outer armature and back contact of relay 32 toground. The circuit for relay 31 may be traced from battery, relay 31, lefthand armature and back contact of relay 28 to the upper outer armature and back contact of relay 32 as above. traced. The operation of relay 30 connects thetip and ring conductor from jack 7, through condensers 3T, armature and front contact of relaySO conductors 36, through the right-ham; wind ings of repeating coil 33 and condenser 34:. The operation of relay Sl disconnects the section 11 of trunk C from the portions terminating in jack 7 and plug 15 so that'no circuit operations can yet. take place at the incoming end of the trunk at the toll board. The flashing of the lamp 10 indicates to the toll switchingoperatorthat a connecw' tion is desired oven trunk C.

Another circuit 15 completed by the open ation of relay 26 for relay 35 as follows:

batter windin of rela '35 armature andfront contact of relay 26 to ground. The operation of relay 35 connects battery and ground through its upper and lower inn'er' armatures and front contacts to conductors 36 for a purpose to be later explained.

The toll switching operator at li answers the flashing signal of lamp 10 by actuating her talking key 12 to connect her telepl'ione set 14: across the talking conductors of the;

trunk. this circuit to the A operator or to the toll. operator but merely listen for the calling;

subscriber at line it to pass his number to the toll operator when a'connection is cornpleted so that she may record the toll con nection on a ticket in the usual manner. The

28 also opens'the circuit for relay 31. so that the connection from the operators telephone set 14 will now he completed through the repeating coil 33 and conductors 36 to the portion 11 of trunk C. if V Another circuit will now also be completed from battery and ground at the upper and inner lower armatures and front contacts of relay 35 to trunlrC and the toll board. This circuit may be traced as follows: battery and ground from the lower inner and upper arinatures and front con tacts of relay 35, upper and low of relay 38, make-before-break contacts of relay 39, right-hand windings of repeating" coll 83, conductors 36, armatures and back contacts of relay 31, truck G armatures and windings She will, however, not talk over luu i lit.)

back contacts of relay 40, left-hand windings of repeating coil 41, upper and inner lower armatures and back contacts of relay 4L2, windings of relay 43, armatures and back contacts of relay 44-, through the loop. connection at these armatures and back contacts. This circuit causes the operation ofrelay 38. Relay 38 in operatlng closes a circuit the steady lighting of lamp 10 as "follows: battery, lamp 10, armature and back contact of relay 27, lower armature and front contact '1 relay 38 to ground. The steadyplighting of lamp indicates to tlictoll switching operator at B that the trunk connection has been extended to the toll board.

The same circuit that causes the operation of relay 38 also causes the operation of re lav. 43 which rela in. ooeratin closes a circuit for the lighting of lamp 17'as follows: battery, lamp l7, right-hand armature and back contact of relay 4&5, armature and front contact of relay 4:3 to ground. It will henoted that this lamp 17 at the toll board can not be lighted until ihe toll switching operator is ready to listen for the subscribers number as it is passed to the toll open ator.- I

The lighted lamp 17 indicates to the toll operator that a toll connection is desired and this operator now proceeds to answer the call by inserting plug 18 into jack :20 and to connect her telephone set 21 through the cord D and the tip and ring conductors trunk C. The connection from the toll operators: telephone set through the tip and ter1ninals of plug 18 and jack 20 extends as noted. to the right-hand winding of repeating coil 41. The circuit connection through trunk C to the cord A extends from the left-hand windings of repeating; coil 41 and over back contacts and armatures oi relays 4:0 and 31. armatures and front contacts of relay 30.1

' condensers 37, tip and ring terminals of jack 7 and plug 6, repeating coil windings of cord A, tip and ring terminals of plug 2 and jack 3 and tip and ring conductors of line 1, while the connection to the toll switching operators telephone set 14 extends through the conductors 36 and the windings of repeating coil 33 from trunk C.

When the trunk circuit was closed to the toll switchboard and relay 38 was operated a connection was closed across the tip and ring conductors at jack"? as follows: from. tip conductor at jack 7, retardation coil 47, the outer right-hand armature and back con tact of relay 27. upper armature and front contact of relay 38 to the ring conductor at jack 7. This direct current bridge across the trunk conductors causes the operation of the usual supervisory relay 49 of cord A to close thensual circuit for extinguishing the supervisory lamp 23 in the cord. This indicatcs to the A operator that the connection to the toll operator has been completed.

The above mentioned operation of relay 4L3 for the lighting of lamp 1? also causes the operation of relay as follows: battery. winding and right-hand armature and back contact of relay 50, outer left-hand armature of relay 50, armature and front contact of relay 43 to ground. Relay 5O op erating closes a locking circuit for itself as follows: battery, winding, alternate contact and right-hand armature of relay 50 lower outer armature and back contact of relay 42 to ground. The operation of relay ,50 opens a circuit for relay 44: so as to preground on the tip and ring conductors of- This battery and ground con trunk C. nccted at the armatures and back contacts of relay 53, right-hand windings of repeat-v ing coil 41. tip and ring terminals or". jack 20 and plug 18. the tip and ring conductors of toll cord D to operate the supervisory relay to light the supervisory lamp.

On the above mentioned insertion of plug 18 into. jack 20 a circuit was closed for the operation of rela Y :31 as follows: battery, tip and ring terminals of plug 18 and. jack 20, windings of relay 51 to ground. The operation of relay 51 closes a circuit for relay 45 as follows: battery, winding of relay 45,

middle left-hand armature and frontcontact of relay 51 to ground. The operation of relay 45 opens the circuit for lamp 17 which is now extinguished and this relay extends a circuit from the winding of relay 42 to the middle left-ham armature and back contact of relay 51 for supervisory purpos as will hereinafter be described.

As relay 53 is not operated at this time due to the operation of relay 13, the above mentioned circuit for the lighting of the supervisory lamp in the toll cord D is provided as above mentioned.

The toll operator now requests the information for the call by answering Long distance and the calling subscriber proceeds to give the information. necessary for completing the connection to the desired subscriber. that is, his own number and the number of the wanted subscriber. The toll operator now prepares the usual ticket of the call and proceeds to extend the connection to the wanted subscribein for example. by inserting plug 59 into jack 60 or the subscribers line 61.

As hereinbetore explained the toll switclr ing operator is included in this connection over trunk C and when the calling; subscribers number is passed to the toll operator the .toll switching operator takes note of this number and inserts the plug 15 of the trunk circuit .G into a multiple jack 22 of the calling subsoriberls line and restores her listening key to normal. This now therefore completes a connection from the calling subscri-bers line 1 through the terminals of jack 22 and plug 15 to the nects the usual busy test circuit normally ating opens the above mentioned bridge cir-i connected to the tip terminal otthe plug and makebefore-break contacts of relay 32. The operation of relay 32 also disconnects the ground at the upper outer armature and back contact from the circuit from relay so that this relay Will 110W release and open the connection fromthe trunk G through the cord A tothe subscribers line 1. The operation of relay 32 also connects the same ground. to the front contact of the armature of relay 54. It Will be notedthat relay 54: Will operate, as the receiver oi. the. subscriber on line 1. is removed from the switchhook at this time, and a loop circuit is therefore completed through the subscribers line to the left-hand windings of repeating coil 33 and the winding of relay 54. Consequently circuits Will noW be closed for the operation of relays and The; circuit tor relay may be traced as follows: battery, winding of relay 55, armature and front contact of relay 54, outer upper armature and front contact 01 relay 32 to ground. The circuit for relay 39 may be traced from battery, Winding oi? relay 89, armature and front contact ofrelay 54- to the above mentioned ground atrelay 32. The operation of relays and 39 closes accircuit from battery at the armature and front contact of relay upper flllllt'ltlll'fifllld front contact of re lay 39, upper winding of relay 38 to ground at the upper armature and front contact of relay 235 to hold relay 38 until the connection is taken down at the toll board. It should be noted that on the operation of relay 39, the original. circuit for relay 38 is opened at the malte-behire-break contact of relay Another circuit is closed by the operation of relay 32,11amcly an obvious circuit for the operation oi relay 27 and this relay in. opercuit across the tip and ring conductors of trunk C throughthe retardation coil 4:7, This cause; the supervisory lamp 23 in the cord at to light which serves as an indication to the A operator to take doWn the c0nnec-, tion between the subscriberot line 1 and the trunk C. y l v 7 Relay 27' inoperatnig its lett-hand armature opens the circuit iorthe lamp 10 and also closes a circuit for the operation of re lay fifyasjiioliovvsz battery, middle] righthand armature and back contact of relay 27,

Winding and make-before-break contacts of relay 57, lower, armature and'iront contact of relay 38 to ground. Relay 57 in operating closesa locking circuit for itself from the above mentioned battery through its lefthand armature and front contact to ground,

thus transferring completely the control over this relay to relay 27.

When relay 39. was operated the battery and ground from contacts of relay 35 were disconnected from thetrunk C to causerelay 13 to release. The release of relay 43 causes a circuit to be closed for the operation of relay 53 which, as hereinbefore. stated, passes through the inner left-hand armature and front contact of relay 51. The operation of relay 53' removes ground and battery -lroin thetip and ring conductors of the cord D and the supervisory lamp. ofthis cord will now be extinguished. This is an indication to the toll operator that a connection has been established through the. toll switching operators position at B.

I As relay 54 is under the control of the calling .subscribers switchhook it follows that when the switchhook is moved up and down the toll operators supervisory lamp. is flashed. In. other Words the circuit for relays 54, 55, 39, 13- and 53 arealternately opened and closed so that relay 53. will alternately connect ground and battery to the tip and ,ring conductors of the cord D to flashthe supervisory lamp,

The above described manipulations and functions of the circuits now therefore complete a connection from the subscriber of line 1 through the toll switching operators position B, thetoll' op'erators cord D to the Wanted subscribers line, Whereas the prior connection throughthe A operators position between-the subseriber o'tline 1 and the toll operator is taken down. "As soon asthe The removal ofplug 18 from'jackQO causes the release of relay 51 and as relay 4:5, is slow to release, a temporary circuit is now completed through the middle left hand armature and back contact of relay 51', tothe left armature and front contact ot'relay 4:5 for the operation of relay 42. The operation ofrelay 42 opens the loop. circuit through the armatures and back contacts or relay data. the tip and ring. conductors of the trunk: C cau sing the release of relay 38.- It should be noted that relay 38 before-break contacts of relay held operated through the normal contacts of relay 39 after the subscriber on line 1 has hung up his receiver and until plug 18 is removed from jack 20. Therefore, the

momentary operation of relay 42 causes the release of relay 38. Relay 38 in releasing trol of relay 57 while lampllO is maintained lighted by the connection to ground at this armature. The locking of relay 63 is, required as relay 42 is only held operated until relay .45 releases. The operation of re lay 63- causes the rcoperation of relay 39 as follows: battery, winding of relay 39, lefthand armature and front contact of relay 63 to the ground at the upper outer armature and front contact ofrelay 32 so that this relay 39 in operating will prevent the reoperation of relay38 when relay 42 releases. The tollswitching operator at B will now, upon receiving this disconnect signal, remove plug from jack 22 causing the release of relay32 which releases relays 27, 57, 63, 39, and 35 so that the trunk G will nowbe restored to normal condition.

.VVhen the tollcoperator desires to complete a connection over the trunk C to a. wanted subscriber this trunk serves as an ordinary tollswitching trunk. The following is a detailed description of the functions ofthe trunk under these circumstances.

The toll operator at D'i-nsertsplug 18 into jack 20 of the trunk C causing theoperation ofrelay 51. The operationof relay 51 causes the operation of relay 53 over a circuit that receives ground; at thearmature and back contact of relay 43. This prevents the; lighting of the supervisory lamp in the cord D. The operation. of relay 51 also closes obviouscircijiits for the operation of relays and 44. The operation of relay 44 connects battery and ground through its armatures and, front contacts to trunk C which causes the operation of relays 43 and 38. The operation of relay 43 releases r,elay 53- so that the supervisory lamp in the cordcircuit B will now light. It is not necessary of course to have the lighting of the supervisory lamp in cord-D delayed by the momentary operation of relay 53. The operation of relay 45 prevents lamp 17 from being lighted on the operation of relay 43.

The operation of relay 38 closes an obvious circuit for the lighting of lamp '10 in the trunk C which indicates to the toll switching operator that a regular toll switching trunk connection is desired over this trunk from a toll operator. The toll switching operator will now therefore operate the talking key 12 and connect telephone set 14 to the trunk. The operation of relay 38 also causes the operation of relay 25 over a circuit as follows: battery, winding of relay 25, left hand armature andback contact of relay 26, lower armature and front contact of relay 38 to ground; The operation of relay 25 connects battery through a resistance to the sleeve circuit of jack 7 to make trunk C busy to A. operators.

The operation of the key 12 causes the operation of relay 28, but this does not perform any useful function at this time as relay 26 is not operated and can not be operated due to the operation of relay 25. The operation of the talking key 12 also closes a circuitfor the operation of relay 64 as follows: battery, left-hand winding of relay 6,4, inner right-hand armature and back contact of relay 2?, lower outer made contacts of talking key 12, inner left-hand armature and back contact of relay 26-to ground. The operation of relay 64 causes a circuit to be closed for the operation of relays 55 and 39 from the above mentioned ground at the inher right-hand armature and back contact of relay 26 through the left-hand armature and front contact of relay 64. The operation of relays 64 and 55 provides battery for a circuit for holding relay 38 operated While relay 39 is actuated. This circuit may be traced as follows: battery lefthand armature and front contact of relay 55 .or battery outer right-hand armature and front contact of relay 64, upper armature and front-contact of relay 39, upper winding of relay 33, loop circuit through the upper and inner lower armatures and front co-ntactsof relay 35, lower winding of re lay 38, and lower inner armature and front contact of relay 39 to ground. ll hen relay 39 operates the circuit loop for trunk C through the upper and inner lower armatures and back contact of relay 35 isopened and a holding circuit for relay 64 is provided at'the lower armature and front contact of relay 39 through the right-hand winding and inner r ithanri armature and lUU ers line.

inturn causes the operation and locking of relay The lamp 1.0 is extinguished by the operation of relay 27 and relays 39 and 55iare released. primarily due to the return of talking ltey 12 to normal and also due to the operation o:t'relay.27. As soon as relay 39 is released relay 6% is released. The releaseolf relay 39 also causes relay 43 tooperate, which in turn .causes therelease ot relaytESand the lighting of the supervisory lamp of cord D. This is an indication to the tolloperator that the connection to the wanted subscriberls line has been established and that she can call him if desired.

. The toll operator calls the subscriber by operating the usual ringing key in cord D and applies QOcycle signaling current over trunk C whichcauses the operation out the alternating current responsive relay 67. Relay (W in. operating closes an obvious circuit for the operation of relay 4:0 and relay in operating. applies signaling current from source 69 over trunk C for the operation of the alternating current responsive relay 70. RelayTO in operating closes an obvious circuit for the operation of relay 71., which in turn applies 20 cycle signaling cur rent from source 72 to the wanted subscrib- Then the called subscriber answers by remo'vingthe receiver from the switchhool: relay Mop-crates, which in turn causesthe operation of relays 39 and as hereinb elore described. The operation of relay 55is required to supply battery to the contacts of relay39 to hold relay 38 operated. When re lay 39operates relay l8 relez ses and causes the operation of relay 53 .to extmguish the supervisory lamp in the toll cord to notity the toll operator that the subscriber has answcred the call. Relay 54. and the relays under its control provide supervision for the toll operator as explained above. The disconnect signals to restorethe circuits to normal are given when the toll. operator removes the plug 18 from jack 20' iirthe same manner as hereinbetore explained.

it is to be noted therefore that trunk C may be used for completing toll connections'in both directions. In one direction the callsrn'iginate through the cord circuit A and the trunk G is in this case used for recording, checking and completing the connection, while calls originating rrom the other direction are handled over trunk G as ii it were an ordinary toll switching trunk.

As statediabove, trunks designed. in ac- .cordance with the, principles of this invention may also be arranged to operatein twoway toll connections between toll sw1tching operators at both ends of the trunk. In

this case, the toll switching operator at the call originating end is the only one concerned in recording and checking the .con-

nection. The invention applied in this manner has been illustrated in Figs. 3 and 4 and equipments at the terminating ends of the trunk are in this case identical. It. will therefore only be. necessary to describe in detail the establishing of a connection in one of line 300 over the two way trunk E to. the subscriber 0i aline, such as e00. The equipments required for a trunk line, suchas E,

for two-way switchingtrunk operations loesides being identical at both ends aifepalso practically identical with the equipmentdtor trunk C as shown in Fig. 1, except fortertain additions relating to the supervision of the calls and the omission of certain arrangements not required in this, type olilcircults. i It should be understood that in the following description, such operations of the ircuit arrangements that are identical with the corresponding arrangements shown in 'l have been briefly mentioned inorder to avoid repetition, while thet'unctions of the circuits that are ditl'erent in this latter method of handling calls have. been clearly brought out.

The subseriberot line 300 is connected to the A operator at A in the usual manner and asks for Long. distance or for the town or city to which. a connection is desired.

.Thisfi operator then extends the connection by inserting plug 300mm ack 307' of the toll line E leading, to the desired town.

This causes the lamp 310. to give a. flashing signal under control of the mterrupter329.

The operation oli relay32o in this case also closes an obvious circuit for relay 865, the

;.1 )urpose ol :which will becomeapparent as the description proceeds. The, toll switching operator at l hherelnatter calledthe outward operator, answers this signal by conneetingher telephone set 314 to the sub scribers line through the cord A as in the previous case. In this case the outward operator will take note of all the details of the call from the callin subscriber instead of the operator at the c stant end and this operator will act asa recording, toll'switcln in and completing operator, in the manner direction, for example, from the subscriber ated in the previous case, and the circuit for lamp 410 may in this case be traced as tact of relay 26 to ground. The steady illu-inination of lamp r10 indicates to the inward operator at Ur that a connection is desired to a subscribers line, whereas the flashing of lamp 310 indicated to the outward ope *ator that an outward connection over toll line E was desired.

The inward operator. now connects her telephone set 414 to the toll line E and as this inward operator is thereby connected in direct communication with the outward operator and also the calling subscriber, the inward operator will now ask the calling subscriber for the number of the wanted subscribers line. The inward operator on receiving this number inserts plug 420 into jack 418 of the wanted subscribers line 400 whilethe outward operator listens to the number passed and records it on the ticket. llhe outward operator then asks the calling subscriber for his own number records it on the same ticket and completes the connection from the trunk E through to the calling subscriber by inserting plug 315 into the multiple jack 322 of line 300.

When the outward operator has thus recorded and checked the call, the same supervisory functions are performed as was described in the previous case, permitting the operator at A to disconnect her cord from the calling line and from'the jack 307 which is now made busy. The outward operator will, of course, remove her telephone set from the toll line and when the connection is completed in this manner the lamp 317 will light with steady glow if the calling subscriber of line 300 had in the meantime replaced the receiver on-the hook, or if the plug 315 was inserted into the jacket another subscribers line. The circuit for lamp;

317 may be traced as follows: battery, lamp 317,, lower outer armature andfront'contact of relay 332, inner left-handarmature and back contact of relay 354; If the subscriber of line 300, however, had not replaced the receiver on the hook, this relay will be actuated on the connection of plug 315 into I jack 322 and consequently prevent lamp 317 tinguished.

connection to the wanted subscribers line 400, relay 435 operated over a circuit as follows: battery, winding of relay 435, inner right-hand armature and back contact of relay lower armature and back contact of relay 465, upper outer armature and front contact of relay 432 to ground. This circuit is closed due to the obvious operation ofrelay e32 on the insertion of plug 420 into jack 118. The operation of relay 435 connects battery and ground to the two conductors of trunk E so as to cause the release of relay 338, as relay is held operated due to the operation of relays 332 and 365. other words, battery and ground at both ends of the trunk E through the contacts of relays 335 and ass are connected so that no current will flow over the trunk E, consequently on the operation of relay 435; relay is released and lamp 310 lighted (.ue ';o the ob *ious circuit closed therefore through the lower armature and back contact of relay 338'and inner right-hand armature and back contact of relay 326.

This signal istaken by the outward operator as an indication that the wanted sub scribers line has been connected to trunk E and that this subscriber may now be rung. The outward operator will now therefore actuate her ringing key 366 to connect ringing current through the trunk E to the Wanted subscribers line. The circuits for ringing the wanted subscriber are obviously similar to the circuits for ringing a wanted subscriber in the previously mentioned case where the trunk C is used as an ordinary switching trunk and will therefore not be described in detail. When the called subscriber answers by lifting his receiver from the rack, relay 435 is released due to the operation of relay 454,. thus permitting relay 338 at the outward operators position to reoperate and cause lamp 310 to be exlhe extinguishing of lamp 310 will indicate to the outward operator that the called subscriber has answered the connection. It is evident then that by this means lamp 310 will be under direct control tne called subscriber. That is, it will light when the called subscriber hangsup his receiver and become extinguished when he removes his receiver from the hook. Similarly, the calling subscriber controls by his switch'hook the lamp 317 as hereinbefore stated.

When either of the subscribers hang up the receiver. signals are given to the outward operator that disconnection is desired. For example, if the calling subscriber hangs up his lamp 410. The lighting of this lamp 410 serves as a disconnectsignal to the inward operator and this operator takes down the connection and restores the circuits to normal by removing plug l-QO-trom ack 418.

it is evident that a call incoming to the toll switching operator at F and originated by the A operator at A may be handled in the same manner as thelast call described.

WVhat is claimed is:

1. In a toll switching system, a trunk, a toll switching operators position one end of the trunk, a recording and completing operators position at the other end of the trunk, signaling means for calling the toll switching operator, signaling means for calling the recording and completing operator, and means responsive to the answer of the toll switching operator to said first signal for disabling the same and actuating the second mentioned signaling means.

2. In a telephone system, an A operators position, a toll switching operators position, a trunk terminating at its outgoing end at said positions, a signal at said toll switching o iierators position, means responsive to the seizure of the trunk by the A operator for actuating said signal, and means controlled by the toll switching operator for disabling said signal for connecting said operator with the A operator and for connecting both 01" said operators with the incoming end of the trunk.

3. In a telephone system, an A operators position, a toll switching operators position, a trunk terminating at its outgoing end at said operators positions, a signal at said toll switching operatoids position, means responsive to the seizure of the trunk by the A tn'ierator for actuating said signal, tor opening the trunk between the outgoing and incoming ends and for connecting the A operators position to the toll switching operators position, a toll switching operators telephone set, and means responsive to the connection till oil said telephone set to the outgoing end of the trunk for disabling the said signal and tor reconnecting the outgoing and the incoming ends 01 the trunk.

41-. In a tclepl'ione system, an A operatofs position, a toll switching operators position, a trunk tcrn'iinating at its outgoing end at said o iierators positions, a signal at said toll switching operators position, means respon sive to the seizure oi the trunk by the A oper ator for actuating said signal in a distinctive manner, for opening the trunk between the outgoing and incoming ends of the trunk and for connecting the A operators position to the toll switching operators positions, a toll switching operators telephone set, means for connecting said telephone set to the outgoing end of the trunk, and means responsive to said connection for disabling said signal,

for reconnecting the outgoing and incoming ends of the trunk and for actuating said signal. in a different distinctive manner.

5. In a telephone system, an A operators position, a toll switching operators position, a recording and completing trunk terminating at its outgoing end at said operators positions, signa'l associated with said trunk at the toll switching operators position, a signal associated with the incoming end of said trunk, means for actuating said first mentioned signal in a distinctive manner in response to the seizure of said trunlr'by said A operator, atoll switching operators telephone set, and means for connecting said set tothe trunk for disabling the first mentioned signal and actuating said last mentioned signal and thereafter actuating said first mentioned signal in a different distinct manner.

6. in a telephone system, an A operators -position,'a toll switching operators position phone set to the trunk, means responsive to said connection for disabling the toll switching operators signal, for actuating the toll operators signal, and for thereafter reactuating the toll switching operators signal in a diii'erent distinctive manner, means respousive to the seizure of said trunk by said toll operator, for disabling the toll operators signal and means thereafter responsive to the disconnection of the toll switching operatofls telephone set from the trunk and the eaten sion at the outgoing end oi": the trunk at the toll switching operators position, for disabling' the toll switching operators signal, and opening the connection through the trunk to the A operators posit-ion.

7. In a telephone system, an A operators position, a toll switching operators position, a recording and completing trunk terminating at its outgoing end at said operators positions, a toll opcrators position at the incoming end of said trunk, signals at said toll switching operators and toll operators positions, means responsive to the seizure of said trunk by the A operator for actuating the toll switching operators signal in a distinctive manner, a toll switching operators telephone set, means for connecting said telephone set to the trunk, means responsive to said connection for disabling the toll switch ing operators signal, for actuating the toll operators signal and for thereafter reactuating the toll switching operators signal in a different distinctive manner, means responsive to the seizure of said trunk by said toll operator for disabling the toll opera'tors signal and means thereafter responsive" to the disconnection of the toll switching 0perators telephone set from the trunk and the extension at the outgoing end of the trunk at the toll switching operators position, for disabling the toll switching operators signal, for opening the connection through the trunk to the A operators position, and for establishing a busy condition at the outgoing end of the trunk terminating at the A operators position.

8. In a telephone system, an A operatorsposition, a toll switching operators position, a recording and completing trunk terminating at its outgoing end at the A operator s and the toll switching operators positions and at its incoming end at the toll operators positiomsign-als at the toll switching operators and toll operators )ositions,means.

responsive to the seizure of said trunk at theA operators position for actuating the signal at the toll switching operators position in a distinctive manner and for disconnecting the incoming end of the trunk from the outgoing end, a toll switching operators telephone set, means for connecting said telephone set to the trunk, means responsive to said connection, for disabling the toll switching operators signal, for reconnecting the incoming end of the trunk to the outgoing end, for actuating the toll operators signal and for thereafter reactuating the toll switching operators signal in a different distinctive manner, means responsive to the seizure of the trunk by the toll operator for disabling the toll operators signal, and means thereafter responsive to the disconnection of the toll switching operators tele phone set from the trunk and the extension of the outgoing end of the trunk at the toll switching operators position, for disabling the toll switching operators signal and for disabling the connection at the outgoing end of the trunk leading to the A operators position.

9. In a toll switching system a trunk, an A operators and a toll switching operators position at each end of the trunk, means for initiating an outgoing call over said trunk by either of said A operators, means for recording and checking an outgoing call by the toll switching operator at the call originating end, and means for completing said call by the two toll switching operators.

10. In a toll switching system, a trunk, an A operators and a toll switching operators position at each end of the trunk, means for initiating an outgoing call over said trunk by either of said A operators, meansfor re cording and checking an outgoing call by the toll switching operator at the call originating end, means for completing said call by the toll switching operators, and means for making the trunk busy to the A operators when a connection is extended through the toll switching operators positions.

In witness whereof, I hereunto subscribe my name this 2nd day of September, A. D. 1926.

RAY S. WILBUR. 

